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Asbestos Insulation Identification Guide

Asbestos use was only banned within the last few decades, and many homes still contain it. Our recent discoveries about its dangers didn’t, unfortunately, come with a quick fix for all the millions of houses that were built with it.

Maybe you’re moving into a new home or just coming to the realization that your current home could contain asbestos. Either way, it’s important to know how to identify this hidden threat so that you can keep yourself and your loved ones safe.


Asbestos comes in different colors: white, off-white, cream, tan, yellow, gray, brown, and blue. It’s easier to ID from its texture. It is a long, thin, needle-like fiber. It can be formed as wool-like loose-fill, corrugated cardboard-like wrappings, semi-solid or foam-like blocks, and snow-like spray-on.

Do You Need to Be Worried?

Before we look at how to identify various types of asbestos insulation, you should first establish whether or not it is even possible it exists in your home.

While asbestos was extremely common in many building products throughout the 1900s, most were banned in 1989 in the United States. (This may vary depending on the country—the UK banned asbestos in 1999 and Australia’s ban took place in 2003.)

To be extra safe, let’s tack on about a decade after the ban to account for the transition away from asbestos since many companies may have been granted leeway to use up inventory or find new suppliers.

That means if your home was built anytime after the year 2005, you are likely safe—at least in the United States. Similarly, if you live in a country with a later asbestos ban, like Australia, tack on about 10-15 years after its ban just for safety’s sake; the dangers of asbestos are no joke.

However, if your home was built or remodeled at any point before 2005, you will definitely want to learn more about asbestos and how to identify it just in case some part of your home may contain it. 

Where to Look

The first step to identifying asbestos is knowing where to look in the first place! With that said, it is such a versatile and useful material that it was, unfortunately, used in just about every type of insulation you can think of.

Where to look for asbestos in your house: attic, ceiling, wall, boiler, furnace, pipe and electrical box

You should look for potential asbestos insulation in the attics, ceiling, and walls of the home. That includes the walls of closets and crawl spaces, and it was also used in basements.

You might also find asbestos insulation on boilers, furnaces, pipes, and electrical boxes as well. 

Before you go looking for any potential asbestos, be sure to wear proper protective gear and, if possible, avoid touching anything that you end up suspecting may contain it. Any disturbance could release harmful asbestos fibers into the air.

Types of Asbestos Insulation

There are six different types of asbestos insulation, each with its own slightly different characteristics. Let’s briefly take a look at the most dangerous type, as well as the two most common types so that you understand what you’re looking for.

Amosite

Amosite asbestos is a brownish-tinted type of asbestos that may give any insulation that it is a part of a yellowish or almost tan coloring. 

It is the second most common type of asbestos found in commercial building products, so many products that contain it may appear creamy or even yellow in color.

In terms of what it was used in, amosite would most commonly be found in block insulation. It was also often used to insulate pipes, and therefore, it would not be uncommon in wrap insulation.

Crocidolite

Crocidolite, or blue asbestos, has a low heat tolerance compared to other types of asbestos, so it was used the least in insulating materials.

This is good since it is the most dangerous type of asbestos due to its extremely thin, needle-like fibers. 

However, it is not completely absent! It was commonly used in cements instead of insulation—but some forms of spray-on insulation are cement-based. That being the case, it would not be impossible to find crocidolite in spray-on insulation.

It can also be found in wrap insulation for pipes or asbestos blocks.

You should already be cautious if you suspect any of your insulation is made from asbestos, but if the insulation you’re eyeing has a slight blue tinge, be extra wary since it may contain crocidolite!

Chrysotile

Chrysotile asbestos is the most common type of asbestos. It’s so common, in fact, that within the United States, it makes up over 90% of the asbestos that was used in construction!

Close up of Chrysotile asbestos fibers

Chrysotile is white, which is part of the reason that most asbestos-containing materials are primarily white, pale grey, or off-white.

It can be found in any and all types of insulation because not only is it the most common, but it is the most unique and versatile form of asbestos due to it having curly, hyper-flexible fibers. Like other forms of asbestos, its fibers are still sharp and dangerous, though!

Forms of Asbestos Insulation

Loose-Fill

Loose-fill asbestos insulation is a type of insulation that is made up of small particles or pieces of fibrous, almost wooly material. It will typically be found in attic or ceiling spaces, and as you might guess, it is loose and free-moving since it is made up of many small bits.

This makes loose-fill asbestos insulation one of the most dangerous, since the danger of asbestos is in inhaling its tiny fibers!

Loose-fill asbestos insulation will usually be whitish, though it can also be light-mid gray or slightly blue in color.

As mentioned, it is a loose material and appears almost fluffy, and it may bunch into many very tiny clumps of material. If you’ve ever seen fake snow or the shredded latex filling used for pillows, the texture of loose-fill asbestos will be visually similar.

Very old or worn asbestos loose-fill may be darker gray or slightly flattened/denser in appearance than described above, and can look almost like chunks of wool or dryer lint.

If you are familiar with cellulose insulation, it is quite easy to confuse it and loose-fill asbestos insulation at first glance.

Cellulose vs Asbestos Insulation: Easy Way to Tell the Difference

Wrappings

Asbestos was commonly used in pipe wrappings. This type of insulation will look like a few layers of very large cardboard wrapped around a pipe—and that is essentially what it is! 

The outside of this insulation may have an outer casing to help secure it to the pipes, which could come in different colors. To see if your pipe insulation resembles cardboard, you will likely need to follow the pipe until you come across a raw edge where the insulation stops.

Old plumbing pipe wrapped with an asbestos insulator

Once you find a raw edge, the visible corrugation—or “squiggly lines”—in the middle of these wrappings will appear grayish in color, and may be a bit worn out. This wear may resemble dry, crumbling clay.

Indeed, this type of insulation does become brittle and crumbly as it ages—that’s not just how it looks. Remember not to touch anything, as this could potentially release many tiny, dusty asbestos-containing particles into the air!

Blocks

Asbestos block insulation was used by securing pieces of it to the walls to cover them up, similar to how we use foam board insulation now. 

These blocks were generally around 2-4″ thick, but came in many different sizes. They are semi-solid, and may be white, gray, off-white, or even yellowed in color. 

Textures can vary quite a bit between different types of asbestos blocks. Some may appear quite solid and consistent, almost like styrofoam or plant foam, although they may be crumbly or dented due to age and wear. 

Other asbestos blocks may be more fibrous in nature and look as if many balls of cotton were stretched out into wisps and then heavily compressed together, like a giant, super scaled-up slab of felt. 

Spray-on

Spray-on asbestos insulation was very useful due to its nature and method of application. It was easy to get into small, difficult-to-reach areas in need of insulation, or onto overhead spaces like the ceilings and walls of attics.

Spray-on asbestos insulation is white or gray in color. When it comes to visual texture, think of the thick, almost fuzzy-looking layer of frost and snow that can build up on a car’s windshield in winter. (Assuming you live in an area with snow!)

Even if you haven’t seen snow, you might’ve seen the inside of a freezer that hasn’t been defrosted in a long time.

That thick, white, textured layer of icy buildup should closely resemble the textural appearance of spray-on asbestos. The surface of asbestos will be opaque and appear more like cement or plaster, however.

Vermiculite Insulation

Vermiculite is a mineral used for insulation, much like asbestos was. It is most commonly used in attics and crawl spaces.

Vermiculite insulation is a pour-in form of insulation that very strongly resembles a bunch of rocks and gravel, usually smaller than a quarter. These rocky pellets can greatly vary in color, with bits of gray, yellow, white, brown, gold, and silver all being common.

Vermiculite grains

Unlike asbestos, vermiculite isn’t harmful on its own. However, before asbestos was banned, about 75% of vermiculite insulation came from a location in Montana where it was usually contaminated with some type of asbestos.

Zonolite, the brand of vermiculite insulation that came from Montana, is usually made from silvery-gold or gray and brown pellets that are very lightweight. Many of these pellets may have “accordion-like” ridges, much like some flat styles of packing peanuts do.

If you have vermiculite insulation that fits this description, there is a good chance that it is Zonolite and should be tested.

Get the Insulation Tested

If you have any suspicion at all that your insulation may contain asbestos, you need to have it tested to be certain. Outside of testing, there is no way to know for sure if your home has asbestos. If it does, the asbestos will need to be removed (in most cases).

And yes, test even if your insulation is old and you’re planning to replace it anyways! Asbestos needs to be handled by professionals and disposed of in a very specific manner in order to ensure safety.

The removal of asbestos is not, unfortunately, the kind of task you can just DIY. 

I already linked it earlier in this article, but I would encourage you to take a look at the dangers of asbestos, if you haven’t yet, to understand just how serious exposure can be.

Asbestos-related illnesses are slow to develop, but they are relentless and have no cure.

Getting asbestos tested and removed can be a bit pricey, but your health and quality of life are priceless! Living with asbestos is a ticking time bomb, and as is commonly said, no amount of exposure is safe. If you can afford to have it removed, that’s the safest thing to do.

Sources

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https://www.asbestos.com/asbestos/types/

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